Modular Air Handling Units TECHNICAL CATALOGUE

Transcription

1 Modular Air Handling Units TECHNICAL CATALOGUE

2 Preface About air handling units The air handling unit (AHU) is one of the most essential and critical units to be considered when designing an air conditioning system. Air T&D provides a wide range of AHUs for use in various applications from small office premises to larger commercial and industrial applications. Air T&D AHUs, with their plug-and-play design and inherent flexibility, can be configured and combined specifically to meet the exact requirements of any building, no matter what it is used for or who is to work there. Our systems are designed to be the most environmentally friendly and the most energy efficient on the market. This means they have a reduced ecological impact, while, at the same time, keeping costs down by minimizing energy consumption. When combined with the small physical footprint of the system, these features make our AHUs ideal for all markets. About this catalogue This catalogue presents Air T&D s standardized range of AHUs, which includes equipment for air flows between 1,500 m 3 /h and 100,000 m 3 /h, with static pressures of up to 1000 Pa. Special care has been taken in the preparation of the catalogue to ensure a user-friendly document. Only a little effort is needed to obtain a rather precise overview of the air handling unit required, with clear, concise information on the most important characteristics. Based on our experience, these are key data for the start of any project. Additional information can be used to identify each of the characteristics to be taken into account in the precise, complete definition of each apparatus. About Air T&D Air T&D is incorporated in January 2015 in Singapore as a high-tech spinoff of Nanyang Technological University. The company specializes in providing energy efficiency air treatment solutions. Through years of research, our team has developed several cutting edge technologies, such as liquid desiccant based dehumidification and air-conditioning systems, new comfortable and energy efficient air treatment terminals - passive & active thermosiphon beams, etc. So far, we have more than 10 patents granted/filed in the air treatment and distribution topics. The company focuses on providing sustainable solutions for the air treatment and distribution of ACMV systems. Starting from Singapore, the company aims to be a major player in ACMV area in Southeast Asia even all over the world. Our mission, and the essence of our existence, is to identify and realize our customers future needs and dreams, even those that they themselves may not yet be aware of. We can accomplish this goal by paying careful attention to changes in social trends and conducting extensive marketing to win the hearts and minds of customers. It is essential that we offer customers optimum convenience and comfort that are always one step ahead of our competitors by providing customers with the highest quality products, materials, and services for which we, as a manufacturer, will be absolutely responsible. Moreover, we will continue offering products and services that provide customers with fresh excitement and continued enjoyment. Technological Innovation from NTU, Singapore 1

3 Table of Contents 1. Features and Benefits Configurations and Selections Model Representation Judgment of Left and Right Type Quick Model Selection Components and Options Diagram of Functional Sections Pressure Drop of Functional Sections Combination of Commonly Used Function Sections Specifications and Performances Cooling Coil Heating Coil Filter Fan/ EC Fan/ Fan Matrix Wall Humidifier Dehumidifier Energy Recovery Unit Air Disinfector Electronic Dust Precipitator Activated Carbon Filter Silencer Electrical and Automation System Electrical System Automation System Installation and Maintenance Installation of Air Handling Unit Usage and Maintenance...37 Technological Innovation from NTU, Singapore 2

4 1. Features and Benefits Superior Performance High Quality Designed For Maximum Flexibility Industry-leading Energy Efficiency System Optimization Lower Installed Time and Cost Low Noise Emissions Casing Casings are made of aluminum frame with none cold bridge technology. The skeleton and double panel was combined with special designed plywood. The casings have smooth inner surface, which can prevent bacteria accumulation, and effectively improve pre-treated air quality. The casings are suitable for applications with clean air requirements. Panel Panel is designed with none cold bridge double sandwich structure in which the standard configuration of the outer layer is color steel plate, a n d the inner layer is high-quality galvanized steel filling with polyurethane foam material of density of 48 kg/m 3. The Panels can effectively prevent heat transfer. The thicknesses of panels are manufactured to select in three nominal values: 25mm, 35mm, and 50mm. Airtightness Air tightness is achieved by double sealing between the skeleton and panel. The reliable and flexible sealing material ensures good air tightness under either positive or negative pressure conditions. Heat Exchanger Cooling coil is made by seamless copper and aluminum fins. The copper tube and fins are sealed by 12MPa hydraulic pipe expander, which ensures to minimize thermal contact resistance and maximize heat transfer efficiency. We provide four types of standard coil: 2 rows, 4 rows, 6 rows and 8 rows. The standard aluminum fin spacing is 2.5mm. We can also tailor fin spacing upon user request. The coil selection software can calculate parameters such as the number of rows, fin spacing, number of loops so as to optimize the design to meet user's needs. Drain Pan A water tray is located underneath the cooling coil; it is designed to ensure smooth draining of condensed water. The drain pan is coated with PE insulation layer. Filter The basic function of filter is to prevent the accumulation of dust on the internal surfaces of coils and panels, extending the lifetime of the air handling unit. Three types of filters below are provided. 1) Primary Efficiency Filter: The filter material is an up-to-date polypropylene fiber, which provides high dust-holding capacity and high filtration efficiency with lower resistance; it is an ideal choice for pre-filter cell. Technological Innovation from NTU, Singapore 3

5 2) Medium Efficiency Bag Filer: It is made of new composite fiber material, with low resistance, high dust-holding capacity and long life span. The bag filter has reasonable interior space dimensions and allows the filter to achieve the lowest operating cost. 3) High Efficiency Filter: The filter material is ultra-fine glass fiber, which possess low resistance and high efficiency characteristics. Filtration efficiency could be customized by to customer demands; the filter configuration is strictly followed by the air velocity requirement, which ensures the service life under normal operation. Fan/ EC Fan/ Fan Matrix Wall Three options are provided to follow the user demands: 1) Centrifugal fan: The fan uses double-inlet-double-width centrifugal type, with high efficiency and low noise. The fan bearings are from the mainstream brands, which provide self-aligning and self-locking functions. The accuracy of fan dynamic balance is G4.0, and it can significantly extend the lifetime of bearings. Fan selection software can select the most efficient fan model based on actual operating conditions to ensure the fan running in energy-efficient mode. The fan is installed on a damping bracket, and connected with the casing through high-intensity and flame-retardant flexible couplings. 2) "EC" (Electronically Commutated) Fan: The option for fans with brushless motors allows for units with reduced dimensions. Controlled by means of a 0-10V signal even without a frequency inverter, these fans are very versatile and easy to be used. The Air T&D AHU can be equipped with EC motors by customer demand. The advantages for the manufacturer and end user include superior integrated PID control, low noise and vibration, access to a wide range of operation details, etc. 3) Fan Matrix Wall: It is a combination of smaller fans built into a wall section to replace a traditional single large fan. This technology incorporates multiple direct-drive centrifugal plenum fans, assembled in a rectangular array of four to 9+ fans, all discharging into a single plenum. The fans used are specially designed and optimized for use. The use of multiple direct-drive fans operating in parallel improves reliability by providing redundancy. Optimized fan wheel construction and improved internal aerodynamics further enhance energy performance. The advantages are the following: shorten the unit; quiet operation; energy savings through optimized performance; redundancy; lower maintenance costs; and food for retrofits. Fan Drive and Motor For general Air T&D AHU with centrifugal fan, standard V-belt transmission structure is used, with Taper Lock to confine the bush pulleys and narrow side of the V-belt. The wide ramp configuration of the narrow side of V-belt allows it has a higher drive efficiency and higher service life than ordinary V-belt. The squirrel-cage three-phase AC motor will be used in general structure, complying with IP Enclosure Ratings, and F class motor insulation. Motor is placed inside the fan section, and placed on top of the damper bracket through special damping pads, together with the fan. An adjustment device is in the bottom of the motor, which allows easy adjustment of belt tightness. Dehumidifier Air T&D provides the most energy efficient Liquid Desiccant Dehumidification System (LDDS) and Liquid Desiccant Air-Conditioning (LDAC) on the world market. Through the breakthrough on the design and operation of LDDS & LDAC technologies, our products can achieve 30% to 50% energy savings when applied to residential and commercial building HVAC systems. Technological Innovation from NTU, Singapore 4

6 Both LDDS &LDAC have been effectively integrated with various energy sources, including two-way heat pump, chilled water and condensation heat in existing system, and combination of renewable energy and grid power. Some key innovations are implemented, such as Energy Recovery, Vacuum Regeneration, Intelligent Control, Hybrid and Distributed Operation, and Zero crossovers, etc., resulting in industry-leading energy efficiency. Automation System Air T&D provides a complete BMS system, called BSTAR, with controller hardware, data acquisition tool, HMI designer, and control function modules. BSATR can be used as perfect control solution of air handling unit. Using this powerful platform, customers can design basic controls and some advanced functions for Air T&D air handling units: Temperature control Frequency converter operation for constant air flow or duct pressure On-demand control Heating and cooling shunts CO 2 compension control of fans Control of different types of heat exchanger Control of extra fans Control of temperature zones Communication via BACnet or Modbus Monitoring via a C/S or B/S interface Rigging There is a dual-use device provided at the bottom of the container box which allows flexible hoisting for site conditions. The container segments could be separated into different parts and allows easy shipping. The modular design allows easy replacements of AHU components, and makes on-site installation process very convenient. Technological Innovation from NTU, Singapore 5

7 2. Configurations and Selections 2.1 Nomenclature KDZ E D W W: horizontal type, L: vertical type Design serial number Unit height index Unit width index Panel thickness: E=25mm, S=35mm, W=50mm Modular Air Handling Unit Model Sample: KDZE2012DW AHU: Horizontal type; panel thickness is 25 mm; unit width is 20 mm; unit height is 12 mm. Unit height = 12 X X = 1330 mm Unit width = 20 X X 2 = 2050 mm Unit module and size calculation formula: (1) Unit height = height index X panel thickness X 2 + base height (2) Unit width = width index X panel thickness X Judgment of Left-handed and Right-handed Type Criterion When the unit have chilled/hot water pipe, o if the chilled/hot water pipe is at right side, and in the same direction as air flow, the unit is known as right-handed type; o Otherwise the unit is known as left-handed type. When the unit does not have chilled/hot water pipe, o if the access door is at right side, and in the same direction as airflow, the unit is known as right-handed type; o Otherwise the unit is known as left-handed type. Technological Innovation from NTU, Singapore 6

8 Air Supply Air Intake Remark For Air T&D standard units, the access door, electrical wiring connection, and hot water pipe are all located at the same side. If customer has special requirements, please indicate them in the purchase order. 2.3 Quick Model Selection Unit Model Nominal Air Flow (m 3 /h) Air Velocity (m/s) Air Flow (m 3 /h) Fan Impeller Diameter (mm) Technological Innovation from NTU, Singapore 7

9 Note: 1. We suggest choosing unit type under air velocity of 2.75 m /s, and then determining unit size by the nominal air flow. 2. When air velocity > 2.75 m/s, we suggest to install water demister in the unit. 3. If user requests for a nominal air flow greater than 100,000 m 3 /h, please contact us. 3. Components and Options 3.1 Diagram of Functional Sections Functional Section Mixing Section Fresh/ Return/ Exhaust air section Diagram Remarks Functional Section When mixing section is Wet film Name followed by filer, humidification access door needs to section be added. High-pressure/ spray/ microfog humidifier Diagram Remarks Could be installed in cooling coil; need not to have independent section; it takes 600mm section to place separately. Provide drain pan; Could be placed beside cooling coil and share water Demister. Plate type primary efficiency filer section There should have inspection section before this section. Fan section Should have equally air distribution when air supply in middle section; Should have access door for inspection and maintenances. Bag type primary/medium efficiency filer section There should have inspection section before this section. Fan section with diffuser ( 均流段 ) Distribution section Generally be placed behind the fan. Cooling coil Section Water Demister can Silencer be eliminated when wet film is placed after cooling coil. Technological Innovation from NTU, Singapore 8

10 Hot water heating coil section 中间段 Generally used for inspection and maintenances Steam heating coil section Supply air section Electrical heating section Electrical heater should have interlocking control with the fan. Plat Energy Recovery unit Dry steam/ Electrode humidification section Wheel Energy Recovery unit Should leave some room for inspection and maintenances before and after this section 3.2 Pressure Drop of Functional Sections Functional Section Pressure Drop (Pa) Functional Section Pressure Drop (Pa) Mixing section 20 Steam heating section (1 row) 20 Cooling coil (2 rows) 40 Steam heating section (2 rows) 40 Cooling coil (4 rows) 80 Fresh air / return air / exhausted air sections 20 Cooling coil (6 rows) 120 Silencer section 30 Cooling coil (8 rows) 160 Fan section with diffuser 20 Water Demister 60 Humidifier (60mm wet membrane) 25 Heating coil (1 row) 20 Humidifier (100mm wet membrane) 30 Heating coil (2 rows) 40 Humidifier (150mm wet membrane) 45 Heating coil (4 rows) 70 Humidifier (200mm wet membrane) 60 * The testing is under air velocity of 2.75 m /s. Technological Innovation from NTU, Singapore 9

11 3.3 Combination of Commonly Used Function Sections Section Combination 1: External Plate-type Filter + Cooling coil (Water Demister) + Fan This is the most economic combination. The combination 1 is allocated with the basic cooling coil and applied to general central air-conditioning systems. It has the advantages with compact structures, small space occupation, and low investment. Section Combination 2: Mixing + Plate-type Filter + Cooling coil (Water Demister) + Fan It is the most economic combination with primary efficiency mixing air. The combination 2 is allocated with the basic cooling coil and primary efficiency filter. It can handle fresh, return, and mixing air, suitable for the temperature controlling requirements of the normal room. It has the advantages such as compact structure and low cost. Section Combination 3: Mixing Air + Plate-type Filter + Cooling coil (Water Demister) + Heating + Humidifying + Fan It is most commonly used combination for air handling. The combination 3 is allocated with the basic cooling coil, heater and humidifier, suitable for high requirements of temperature and humidity control. Technological Innovation from NTU, Singapore 10

12 Section Combination 4: Mixing + Plate-type Filter + Cooling coil (Water Demister ) + Heating + Fan + Humidifying + Fan with Diffuser + Medium-Efficiency Filter + Air Supply It is mainly used for purifying air. The combination 4 is allocated with cooling coil, heater, humidifier and primary/ medium efficiency filter, suitable for requirements of air purifying and temperature/humidity controlling. Section Combination 5: Mixing + Primary/Medium Efficiency Filter + Cooling coil (Water demister) + Heating + Humidifying + Fan + Diffuser + Silencer + Sub-high Efficiency Filter + Air Supply It is used for high-purifying air-conditioning system. The combination 5 is allocated with cooling coil, heater, humidifier and primary/medium efficiency filter, suitable for requirements of air purifying, temperature, humidity and noise controlling. Section Combination 6: (Top Layer) Air Supply + Medium Efficiency Filter + Middle Section; (Bottom Layer) Mixing Air + Plate-type Filter + Cooling coil (Water Demister ) + Heating + Humidifying + Fan The combination 6 is applied to the places which have the requirements of air purifying, temperature and humidity controlling, and limited spaces. Technological Innovation from NTU, Singapore 11

13 Section Combination 7: (Top Layer) Fresh Air and Primary Efficiency + Plate-type Energy Recovery + Air Return Primary Efficiency; (Bottom Layer) Ventilator + Plate-type Energy Recovery + Middle + Cooling coil (Water demister) + Fan It is an energy-saving air-conditioning system. It is able to recover energy via ventilation, applied to the places which have small both Energy Recovery and air flow. Section Combination 8: (Top Layer) Air Return + Primary Efficiency Filter + Wheel Dehumidifier + Ventilation; (Bottom Layer) Fan + Cooling coil (Water demister) + Middle + Wheel Dehumidifier + Primary Efficiency Filter + Fresh Air It is an energy-saving air-conditioning system. The combination is able to recover energy via ventilation, applied to the places which have large amount of both Energy Recovery and air flow. Technological Innovation from NTU, Singapore 12

14 4. Specifications and Performances 4.1 Cooling Coil User can select coils by accurate calculation from chilled water, hot water, steam and direct expansion types, to provide optimum performance conditions. In accordance with system requirements, copper tube aluminum fin or steel tube-steel fin coils are used in Air T&D air handling units. While copper tubes up to 2x10 5 Pa pressure is used in steam applications, the use of steel tubing is required for higher pressure steam applications. Standard tube diameters used are 3/8, 1/2 and 5/8. In aluminum finned designs, fins are coated with epoxy, providing high corrosion resistance. Cooling Capacity and Water Flow VS Return Air Flow Unit Model Nominal Air Flow (m 3 /h) Cooling Capacity (kw) 2 rows 4 rows 6 rows 8 rows Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Technological Innovation from NTU, Singapore 13

15 Note: 1. Chilled water is supplied at 7 C, returned at 12 C. 2. Under return air condition, entering dry bulb temperature is 27 C, and wet bulb temperature is 19.5 C. 3. The above parameters are for reference only; please contact us for customized working conditions, coil configurations and cooling capacities. 4. The test is under air velocity of 2.75 m /s. 5. Please contact us if user requests for a nominal air flow greater than 100,000 m 3 /h. Cooling Capacity and Water Flow VS Primary Air Flow Unit Model Nominal Air Flow (m 3 /h) Cooling Capacity (kw) 2 rows 4 rows 6 rows 8 rows Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Cooling Capacity (kw) Water Flow (m 3 /h) Technological Innovation from NTU, Singapore 14

16 Note: 1. Chilled water is supplied at 7 C, and returned water at 12 C. 2. Under return air condition, entering dry bulb temperature is 35 C, and wet bulb temperature is 28 C. 3. The above parameters are for reference only; please contact us for customized working condition, coil configuration and cooling capacity. 4. The test is under air velocity of 2.75 m /s. 5. Please contact us if user requests for nominal air flow greater than 100,000 m 3 /h. 4.2 Heating Coil Air T&D uses finned galvanized steel tubes as electrical heater coil material. We also provide stainless steel tubes as alternative coil material. All electrical coils are placed into a galvanized sheet casing. High capacity electrical heating coils can be split into the desired stages upon demand. Heat Capacity and Water Flow VS Fresh/Return Air Flow Nominal Unit Air Flow Under return air condition (dry bulb temperature is 15 C) Under fresh air condition (dry bulb temperature is 7 C) Model (m 3 /h) Heat Capacity (kw) Heat Capacity (kw) 1 row 2 rows 3 rows 4 rows 1 row 2 rows 3 rows 4 rows Technological Innovation from NTU, Singapore 15

17 Note: 1. Hot water is supplied at 60 C, and returned at 50 C. 2. Under return air condition, entering dry bulb temperature is 15 C, and wet bulb temperature is 7 C. 3. The above parameters are for reference only; please contact us for customized working condition, coil configuration and cooling capacity. 4. The test is under air velocity of 2.75 m /s. 5. Please contact us if user requests for nominal air volume greater than 100,000 m 3 /h. 4.3 Filter The basic function of filter cells is to prevent the accumulation of dust on the internal surfaces of coils Technological Innovation from NTU, Singapore 16

18 and panels, extending the efficient lifetime of the air handling unit. Dust accumulation is an unwanted condition which reduces the heat transfer efficiency of coils. Additionally, use of high particle efficiency filters is required for environments where the air must be kept free of air-borne harmful microorganisms (pharmacological production facilities, operating rooms, clean rooms, microchip production facilities). For this reason, various filter classes with the ability to filter particles of various diameters have been developed. Air T&D filter cells are distinguished for their design which reduces filter pass pressure drop by minimizing the rate of filtration. To this end, cell dimensions are designed in proportion to filter dimensions. The special spring clip casing design provides a high level of impermeability. This feature is particularly important for air handling units since it could prevent microbiological proliferation. In addition to these features, filter cells have been designed to facilitate easy maintenance thanks to their wide filter covers and spring clip filter casings. Differential pressure stats for measuring filter occupancy can also be used as an option. In Air T&D air handling units, various filtering options are applied and optimum options are offered depending on the place of use and upon requirements. Filter selection should be done by considering all these properties to extend filter life span and lower maintenance costs. Panel Filter: Manufactured in G3 and G4 classes, these filters are produced from high quality galvanized steel, PVC or fiberglass material. The decisive point in the design of these filters which have a gravimetric efficiency of 85-95%, is creating a corrugated structure and hence a larger filtering surface. Panel filters which can withstand temperatures of up to 180 C are used in Air T&D air handling units for prefiltration to lengthen the usage lifetime of higher particle efficiency filters. Panel filters are allowed to be reused after washing, which lowers the operational and maintenance costs, and thus becomes the most popular filter type of choice. Bag Filter: Manufactured in various classes from G4 to F9, bag filters are produced with galvanized frames as a standard. The filtering element is produced from fiberglass. Its extended surface design leads to low air flow rates, thus facilitating low pressure drops, high dust capturing capacity, long usage lifespan and low energy costs. Bag filters are capable of providing solutions for all types of air handling units. For example, rigid type bag filters with a plastic frame design are popular in the market since they can be used in both downstream and upstream. Pressure Drop for Different Filters under Air Velocity of 2.75 m /s Filter type Initial Pressure Drop (Pa) Final Pressure Drop (Pa) Design Pressure Drop (Pa) G3 plate filter G4 plate filter G3 bag filter G4 bag filter F5 bag filter F6 bag filter F7 bag filter F8 bag filter F9 bag filter H H H Technological Innovation from NTU, Singapore 17

19 H Filtration Performance for Different Filters Filter Type Filter Material Filtration Class Filtration Efficiency Test Method Primary Efficiency Panel Filter Primary Efficiency Bag Filter Medium Efficiency Bag Filter Sub-High Efficiency Filter Synthetic Fiber G % Gravimetric Method G4 > 90 % Synthetic Fiber G % Gravimetric Method G4 > 90 % Synthetic Fiber F % Colorimetric Method Or Glass Fiber F % F % F % F9 >= 95 % Glass Fiber H10 85 % Most Penetration Particle Size (MPPS) Filter Efficiency Configuration for Different Types of AHU Types General configuration Configuration for electronic factory Purification class Class 5 Class 6 Class 7 Class 8 Class 8.3 Primary efficiency G3 G4(F5) G4(F5) G4(F5) G4 G3 Medium efficiency F6 F8 F8 F8 F7 F6 Higher medium /subhigh efficiency H10 F9 Types Configuration for tobacco factory Configuration for pharmaceutical industry Purification class Class 5 Class 7 Class 8 Class 8.3 Primary efficiency G4 G4(F5) G4(F5) G4 G3 Medium efficiency F7 F8 F8 F7 F6 Higher medium / subhigh efficiency H10 Efficiency Comparisons of Air T&D Filer in Europe, U.S.A and China Protocol Filter dimension Filter dimension Unit model * * * * Unit model * * * Technological Innovation from NTU, Singapore 18

20 Filter dimension 490 * Unit model * * * * Note: The table above could only be used as reference for build-in panel filter, filter bag filter. The filter dimensions provided in above tables are under Air T&D s standard. 4.4 Fan/ EC Fan/ Fan Matrix The air handling unit includes a fan cell for the purpose of facilitating air circulation through an aspirator and/or ventilator, depending on the requirements of the environment. While forward curved fans are preferred for AHUs within the low pressure range, backward curved fans can be used for AHUs within the medium and high pressure ranges. In addition to these, fans are commonly preferred due to their efficiency and low noise level operation. Depending on design conditions, plug (without scroll case, single inlet, direct coupled) fans can also be used. Fans used in Air T&D air handling units are manufactured from galvanized sheet metal. Forward and backward curved fans are statically balanced according to the ISO 1940-G6.3 standard. Flexible connection is used between the air exhaust and the unit body to dampen vibrations. Flexible connections which used to connect the ductwork from outside are also available. Diffusers are installed to build interconnections between the fan and other cells. The basic purpose of the diffuser is to distribute the air flow in the subsequent cell evenly within the cell. Performance Features for Different Fans Fan types Forward curved Backward curved Radial Characteristics Wide range for air flow, low noise level, low rotation speed Competitive efficiency, low noise level, flat curve behavior, high strength Competitive efficiency, low noise level, flat curve behavior, high strength Application range Low air pressure, or for occasions with special requirements (e.g. noise level) Large air pressure, large air flow, wide performance range Large air pressure, large air flow Large air flow, medium to Principle of Small air flow range, avoiding to Medium/low air pressure, large high air pressure, especially selection use fans with high rotation speed air flow for purification airconditioning units EC (Electronically Commutated) Motor Fans Depending on global and nationwide research, the highest potential whereby electrical energy saving can be achieved has to do with electrical motors. The leading factor in implementing this responsibility is EC technology with the high energy economy it provides. Technological Innovation from NTU, Singapore 19

21 The EC motor is a DC motor with electronic commutation. This means that the motor speed can be controlled very effectively. The motor speed is controlled by how rapidly the magnetic flux in the motor switches. The permanent magnets of the rotor create the magnetic flux in the motor. Speed control is carried out using a control unit integrated with the motor. Control signal is in 0 10 V, starting at 1.4 V and stopping at <1 V. The EC motor is efficient throughout its operating range and is brushless, requiring less maintenance. The Air T&D AHU can be equipped with an EC motors by customer demand. Details distinguishing it from other products on the market, and some advantages for the manufacturer and end user are as follows: - Process controller, speed control device or driver, electrical filters and overload protection (for motor and electronics) elements are all within the motor. - Low noise and vibration levels are achieved throughout the entire operational range % speed control is available without using additional components. - Fixed performance throughout the full supply current range. - Integrated DC supply source for sensors. - Programmable analogue outlet. - Integrated PID, access to and ability to modify PID parameters depending on the algorithm. - Integrated alarm, access to a wide range of failure, error and actual details throughout the operation period depending on the EEP- ROM memory. Fan Selection System requirements influencing fan selection are air quantity, static pressure, non-standard air density, noise level or use of the fan s operating environment, as well as properties of the useable area and cooling load. Air T&D will select fan types and customize fan schemes on user demands. - The first step in a selection process is to select fan type. If that the fan is to be installed into an AHU, the most common question is whether to select a centrifugal fan in casing or without casing. Centrifugal fan in casing usually has slightly higher efficiency than a fan without casing, but in an AHU it is more vulnerable to the installation effect, which reduces its efficiency. Therefore, for AHUs, a backward curved centrifugal fan without casing is the preferred option for majority of AHUs. - The next step is to select a fan motor. Because of the high efficiency, EC motors should be used whenever possible. Asynchronous AC motors with variable frequency drives are the second option. When selecting the fan size, several sizes are usually able to provide the required airflow and pressure in the operating point. The size, where the operating point is closest to the best efficiency point and motor electrical input is the lowest, should be selected. Fan Matrix It is a combination of smaller fans built into a wall section to replace a traditional single large fan. The custom air handling units they supply using this technology incorporate multiple direct-drive centrifugal plenum fans, assembled in a rectangular array of 4 to 9+ fans, all discharging into a single plenum. The fans used are specially designed and optimized for use. Each fan array is usually controlled by a single variable speed drive, which controls the speed of all fans simultaneously. The use of multiple direct-drive fans operating in parallel improves reliability by providing redundancy. Optimized fan wheel construction and improved internal aerodynamics further enhance energy performance. In a traditional system using direct drive motors, it is common to see motor loads at 1/4th to 1/8th of their nameplate rating for a significant portion of their operation hours, resulting in reduced power factors and Technological Innovation from NTU, Singapore 20

22 lower fan and motor efficiencies. To more closely match site conditions, the fan matrix wall can be tuned by turning one or more fans off to allow remaining fans and motors to be fully loaded at or near peak efficiency. Air flow rates can be varied through use of a variable speed drive, by turning fans on and off, or by using both control strategies in combination. The advantages are listed at the following as the key reasons to employ this fan arrangement: - Shorten the unit - Quiet operation - Energy savings through optimized performance - Redundancy - Lower maintenance costs - Good for retrofits The following is a sample drawing of Air T&D fan matrix wall (with 2 X 3 fan matrix). Technological Innovation from NTU, Singapore 21

23 4.5 Humidifier The humidification unit is used to control the relative humidity of the ambient air by increasing the absolute humidity of air in the air handling unit. The choice of humidification equipment is depending on user requirements for the indoor environment. Various types of humidifiers can be used in Air T&D air handling units according to the application type. Saturated Steam Humidifier The most commonly used humidification method is to use dry steam to humidify the air. The user must provide MPa saturated steam source. We made use of double insulation steam pipe clamp stainless steel as material for dry steam humidification equipment, which has a beautiful appearance, corrosion resistance and extra-long lifetime. We provide a unique muffler measures to enables absolutely silent injection process. The double insulation design ensures that there is no condensed water discharge phenomenon occurs inside the tube, and can also achieve high-precision humidification control. Wet Film Humidifier Wet film humidifier is the most simple and economical humidify equipment; users only need to provide water. Wet film humidifier characterized by increase humidifying space, could also eliminate or replace the use of water flap. However, due to the presence of humidification hysteresis in control process, wet film humidifier are not suitable to be used in occasions with high requirements on cleanliness and humidity. It is commonly used in comfort air conditioning systems. Immersed Electrode Steam Humidifier Electrode humidifier makes use of conductivity of water to heat up and produce steam for air humidification, and it is suitable for offices, manufacturing plant, computer rooms and sterile field. Due to its own characteristics, it will not cause fire when working under low water capacity; it is a safe and reliable humidification method. However, it does have certain requirements on water quality; generally, it uses tap water, but cannot use purified water or distilled water. The electrode humidifier can perform precise adjustment of humidification. Spray Air Washer Humidifier T he working principle of h igh-pressure spray / high-pressure fog humidifier is to increase pump pressure, and spray high-pressure water through the nozzle. Due to the small size of spray particles ejected out from high-pressure nozzle, it has high humidification efficiency, humidity control precision can be controlled within ±8 ~±12%. It is suitable to use in manufacturing industries. Selection of Humidification Type Humidification Type Isothermal humidification Equal-enthalpy humidification Humidifier types Saturated steam humidifier Electrode humidifier High-pressure spray humidifier Wet film humidifier Humidification principle Introduce steam directly Current pass through water and heat up the water to produce steam Spray high-pressure water through nozzles, exchanging heat with air and then evaporating Water evaporate when air pass through the wet film Humidification capacity Determined by humidifier itself Determined air condition before humidification and humidifier itself Technological Innovation from NTU, Singapore 22

24 Application range Suitable for high-precision control occasions Suitable for general precision control occasions 4.6 Dehumidifier Quality HVAC systems that deliver consistent cooling and precision control are essential to the overall operations and health of most commercial facilities. Nowadays, engineers and property owners are taking dehumidification as a key consideration in the design of HVAC systems. The benefits are clear: the removal of moisture in air could improve indoor air quality (IAQ), (or most of time we say IEQ, indoor environment quality) as well as provide better indoor comfort level, in the meanwhile supporting facility operations and maximizing the life of building, furnishings and equipment. Air T&D dehumidification options help significantly reduce moisture-related damage and degradation to the facility and other assets, preventing peeling paint, odor problems and loss of structural integrity. From the moderate dehumidification requirements of typical office environments, to moisture-sensitive museums, printing plants and surgical suites, the comprehensive approach of Air T&D offers solutions that are right for users facility and budget. Traditional Dehumidification solution Name Cooling Dehumidification (Cooling Method) Rotor Dehumidification (Chemical Method) Feature Scope of Application Rules of Selection Cooling the air below the dew point, then removing the condensed moisture Applying for the temperature range higher than the dew point Dehumidifier can remove all the indoor moisture load Dehumidifying by the adsorption of solid drier Applying for low dew point Reasonably distribute air flow, maximize the dehumidifier capacity to achieve the best dehumidifying effect Note: Please contact our company if the customers have requirements of dehumidification; we will design the units according to customers' specific parameters. Air T&D Innovative Dehumidification Solution Air T&D provides the most energy efficient Liquid Desiccant Dehumidification System (LDDS) and Liquid Desiccant Air-Conditioning (LDAC) on the world market. Through the breakthrough on the design and operation of LDDS & LDAC technologies, our products can achieve 30% to 50% energy savings when applied to residential and commercial building HVAC systems. LDDS: a series of standard products with single unit air treatment capacities ranging from 500 m3/h to 4,000m3/h. Since the products are modular designed, we can meet all users need through module combination. Our professional design team can also tailor the design for any special requirements from customers. LDAC: The LDAC are designed for general building HVAC applications to realize independent control of air temperature and humidity, with air flow ranging from 1000 m3/h to 40,000m3/h. LDAC can integrate with existing HAVC components easily to supply cool, dry and clean air into occupied space. Both LDDS &LDAC have been effectively integrated with the following energy sources: Technological Innovation from NTU, Singapore 23

25 Utilize two-way heat pump to supply cooling and heating energy for dehumidifier and regenerator simultaneously. This integration enables the system to operate independently and is suitable for the application that renewable and cooling energy are not conveniently available Integrate the LDDS with existing HVAC systems to employ chilled water and condensation heat as external energy to drive the de-humidifier and regenerator, respectively. Combine the renewable energy and grid power to drive LDDS operation. Our intelligent control technology enables the system to operate in hybrid mode and seek a maximum usage of renewable energy while taking the grid power as an auxiliary. Key Innovations Hybrid Operation: In conventional systems, desiccant solutions continuously exchange between dehumidification and regeneration columns in order to maintain the pre-specified concentrations. Our patented hybrid operation technology makes the desiccant solutions cycling inside the each tower for a specified concentration range, and exchanges the solutions once the limit is reached to avoid the energy waste and improve the system efficiency. Energy Recovery: Conventional systems require a large amount of heat energy for solution regeneration. Most of the heat energy is wasted as the regenerated air is discharged directly. Our LDDS &LDAC are able to recover most of the heat with a hot water pipe energy recovery device. This structure innovation results in 60% regeneration energy saving com-pared with the current technologies. Vacuum Regeneration: High desiccant solution regeneration temperature has been become a key barrier for wide application of LDDS & LDAC. Our novel designed absorption-based liquid desiccant regenerator can drastically reduce the regeneration temperature from 80 C (conventional type) to 40 C, thus most low grade energy, such as solar energy, wasted heat from chiller, can be reused effectively to concentrate the desiccant solution. Moreover, no fan is equipped so that the system is more energy-efficient and reliable. Intelligent Control: The ability of liquid desiccant to remove water vapor from air is determined by the temperature, flowrate and concentration of the solution. Air humidity ratio of dehumidifiers can be controlled by regulating the three variables. We have developed an integrated controller with intelligent algorithm. Through the advanced control technologies, the humidity ratio of supply air can be accurately controlled from 3g water/kg dry air to 10g water/kg dry air. Distributed Operation: In commercial and residential building applications, dehumidifiers are usually inside the AHU rooms located in different floors. The heating sources, either waste heat from chiller or solar energy, are available in plant room or on the roof top. The hybrid operation provides a possibility for dehumidifier and regenerator running in different places which offers an opportunity for LDDS &LDAC being efficiently applied in building ACMV systems. Zero crossovers: Air T&D s innovative design on solution distribution nozzle and vane type mist eliminator can achieve both zero solution crossovers and minimal pressure drop. 4.7 Energy Recovery Unit Energy Recovery units (ERUs) used in Air T&D air conditioning systems preheat or precool the fresh air taken in outdoor conditions using exhaust air, bringing the enthalpy and temperature of fresh air to interior space conditions. However, in these systems, if energy is taken from another system, Energy Recovery does not occur. According to VDI 2071, the transfer of mass is not Energy Recovery. Thus, Energy Recovery cannot be achieved by mixing air. Technological Innovation from NTU, Singapore 24

26 Sensible heat transfer is made primarily in ERUs. Latent heat can be transferred depending on the structure of the HRUs. Air T&D provides three types of ERU for different application places, as shown in the following table. Selection of Energy Recovery Unit Name Wheel Energy Recovery equipment Plate Energy Recovery equipment Energy Recovery loop Properties High Energy Recovery efficiency, Preventing air contaminations, Completely isolated air cross contamination, high capital reliable operation, Sensible flow, sensible Energy cost. Sensible and latent heat (total and latent heat (total heat) Recovery only heat) recovery recovery Range of application Products used in civil and industrial buildings Suitable for small air flow, small recovery capacity occasions such as hospital and laboratories Special occasions such as animal laboratories Note: Please contact us before ordering, we would provide dedicated design to meet user requirements. Performance for wheel Energy Recovery Air velocity m/s Recovery % efficiency H /W D Weight Air pressure drop Pa Models Air treatment capacity mm mm kg 500 m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h Technological Innovation from NTU, Singapore 25

27 2800 m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h m 3 /h Air Disinfector Building design and construction have been impacted by ever evolving ASHRAE standards, and owners are becoming more and more focused on not only heating/cooling/moving so much air, but also making sure the HVAC design provided is energy efficient. Along with energy efficiency, many owners are also looking for HVAC designs which will maintain and/or enhance indoor air quality. Today people spend more time indoors than ever before. It has been proven that the air we breathe can make us feel unhealthy, deficient and tired. This in fact does affect our well-being along with productivity. People expect the air they breathe to be reasonably safe and comfortable. Yet indoor air can be laden with mold, mildew, dander, bacteria, and viruses. As a result of those paradigm shifts, many owners and engineering firms are turning to disinfection to meet the new and emerging requirements. Disinfection by UV and Ozone Name Disinfection by UV Ozone Generator Feature Scope of Application - The dose of Ultraviolet Germicidal Lamp for Air-conditioning System needs to be in the range of µ W s/cm 2 (the product of the average intensity of illumination and the time of wind through the UV field) - the sterilization rate of the general bacteria and viruses can reach more than 90% - can prevent the cross-infection effectively Disinfection on the functional segments of Air Handling Units in static and dynamic states: filter, cooling coil, condensate drain pan and etc. - Disinfection: Ozone is a kind of board-spectrum, high-efficiency and fast sanitizer. It can kill all kinds of bacteria, virus and microorganism which can make people and animals sick. - Detoxification: Ozone can efficiently remove the toxic gases such as CO, NO, SO 2 and mustard gas by oxidation reaction. Ozone owns the functions of deodorant and deodorization. Dynamic disinfection of air flow. Technological Innovation from NTU, Singapore 26

28 Rules of Selection The selection for the power and position of UV disinfection is according to the average intensity of illumination and the exposure time. The model selection is according to the room volume and cleanliness class. Clean class 0.1K 1K 10K 100K Concentration (mg/m 3 ) 4.9 Electronic Dust Precipitator High-voltage electrostatic air-purifying sterilizer uses high voltage to ionize the air, let the particulate matter and the microorganism in the air be charged through the polarized area, then collect the charged particles through the duct-controlling area which is charged by opposite charges to break the cell wall in a moment and kill the bacterial and virus. The creative points of such technology are: The resistance in the duct-controlling area is small, a n d duct-removing area can achieve the maximum of board electrostatic dust removing through unit ventilation cross-section. The polarized area, the duct-controlling area and back- pressure area form three-area high-voltage electric fields, which have the functions such as killing bacterial, removing dust and odor with high efficiency. Performance Parameters of High-Voltage Electrostatic Air-Purifying Sterilizer Items Performance Items Performance Index Index Dust removing PM1.0 >=98.9% Bactericidal efficiency after 30 >=99.92% efficiency and purifying effect by PM2.0 >=99.5% minutes from start up Purifying efficiency of Methanol 0.03mg/m 3 one-time pass (concentration after 1 hour after start-up) PM5.0 >=99.4% Purifying efficiency of TVOC 85% PM mg/m 3 The concentration of Ozone generated during the operation 0.005mg/m 3 Bactericidal efficiency by onetime pass >=94.69% Continuous operating results Efficiency decreasing <=0.1% Equipment Resistance 30Pa 4.10 Activated Carbon Filter Principle Activated Carbon Chemical Filter can clean the chemical pollutants in the air, such as odorant, ammonia, SO2, VOCs and etc., satisfying the requirements of industry condition, environment protection and civil use. We need to know the followings before we select the model of Activated Carbon: type of the pollutants, concentration of the pollutants, a i r temperature and relative humidity. Technological Innovation from NTU, Singapore 27

29 Carbon filters can be used efficiently up to 40 C temperature and 70% relative humidity. In case high efficiency pre-filtration (F7-F9) is used in applications, filters are not filled with dust particles which allows them to continue their true function of capturing gas molecules more efficiently and for a longer period of time. Absorptivity of regular carbon decreases with increasing humidity, yet this is not an issue for active carbon. Furthermore, in cases where the contact time is increased by lowering flow rate, active carbon filters operate more efficiently. Another point which should be taken into consideration in carbon filter selection is that they are 10-20% more adsorptive when loaded to 50% of their total capacity. Properties Manufactured as cylindrical cartridges, active carbon filter is used in the filtration of harmful and malodorous gases. These filters are preferred in Air T&D air conditioning systems in cases where the return air as well as fresh air needs to be purified for these harmful and malodorous gases. Our company uses the Activated Carbon Casing which can be reused, having two types of the frame: plastic and metal. Customers can entrust the professional factories to replace the Activated Carbon (experienced users can replace the Activated Carbon by themselves), and they can reuse the Activated Carbon after its regeneration as well. This will decrease the shipping fare of customers. Activated Carbon Chemical Filters should be allocated before or behind the conventional filters. The former is for protection, preventing the duct from obstructing the microporous structure of the Activated Carbon. The latter is for pre-protection, preventing the powder of the Activated Carbon from polluting the ventilation system. Harmful Gases in Typical Places Typical Harmful Gases Places Typical Harmful Gases Places Methanol Interior Decoration, Odorant, VOCs Interior Decoration, Airports, Hospital Offices Acid Gases Paper-making, Micro- Stink livestock farm, Slaughter House, electronics Sewage Treatment Plant Alkaline Gases livestock farm, Micro- Mercury Vapor Electroplating, Electrification electronics Sulphur Oxides, Nitrogen Oxides Micro-electronics Radioactive Gases Underground Projects, Caves, Nuclear Power Plant 4.11 Silencer Silencers are elements which bring noise levels to desired levels while attenuating noise within air handling units or ventilation ducts. Sound attenuation is achieved through the porous material found within the silencer. In Air T&D applications where low noise levels are called for, silencing units are placed in front of and/or behind fan cells. The sound attenuation is achieved by the sound absorbent material which has been manufactured from foam glass with a fire rating of A2. The foam glass is selected in the range of kg/m 3. Properties Frontal surfaces of silencers should be covered with sheet metal to prevent the air from passing directly Technological Innovation from NTU, Singapore 28

30 over the foam glass material. If the air would be passed directly over the foam glass material, very high pressure losses will occur in the porous environment, hence on the foam glass. While silencers serve basic their function of attenuating sound, they cause pressure losses resulting from air flow within the air handling unit or the ventilation duct. For this reason, silencers that are placed at specific distances should be designed to make sure their frontal surfaces that are perpendicular to air flow will lead to minimal pressure drops, hence eliminating needless pressure losses. For this reason, frontal surfaces of silencers have plain, triangular and curved forms. Pressure losses occurring within the silencer cell has been examined for a simulated silencer cell selected for the experimental setup. Silencer Selection Name Resistive Silencer Micro-perforated Silencer Structure Feature - Applying the galvanized steel to form the frame. - Using the sound absorbent material inside and the screen board on the surface. - Being able to absorb noise of different frequencies by changing the thickness of resistive silencer. The sound attenuation dose is large and the head loss is small. Applying the galvanized steel and other steel materials. - Being able to broaden the range of silence frequency and control the silencer with different central frequency by changing the perforation diameters and rate. - The head loss is small and regenerated noise is low. Scope of Application - The maximum air flow velocity is 10 m/s. -Suitable for normal air-conditioning - The maximum air flow velocity is 20 m/s. - Suitable for clean air-conditioning systems or easily dust-collecting cases. Studies have shown that intake and discharge frontal surfaces of silencers should have a curved form. It has been observed that this provides a 26% reduction in pressure losses occurring within the silencer cell. Experimental studies have also shown that maximum sound attenuation is achieved with the silencer with curved intake and discharge surfaces. For this reason, silencers with curved intake and discharge surfaces are preferred in Air T&D air handling units. Performance parameters of resistive silencer Length of Values of noise attenuation under different Octave Band (db) Silencer (Modulus) 63Hz 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz 6M M M Performance parameters of micro-perforated silencer Length of Silencer Values of noise attenuation under different Octave Band (db) (Modulus) 63Hz 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz 6M M M Technological Innovation from NTU, Singapore 29

31 5. Electrical and Automation System 5.1 Electrical System According to customers' different requirements, Air T&D air handling units can select multiple electrical controlling schemes, such as traditional direct starting, star-triangle starting and variable-frequency starting/control. The main electrical components and elements of the control cabinet are all the international mainstream products, in order to ensure the accurate controlling and electrical safety. The Air T&D AHU is a ready-to-install functional part with an internal cabinet for all control and safety apparatus. Only the electrical power supply and the control signals required from superordinate control systems need to be connected to the installation site. It is factory tested and the test report is included in the delivery. Air T&D can extend the controlling functions such as local/remote switch control, BA control, interlocking between fan and fire damper, interlocking between fan and other equipment, etc. Schematic Diagram of Direct Starting (Motor Power 11KW) Technological Innovation from NTU, Singapore 30

32 U11 V11 W11 Display U12 V12 W12 U11 V11 W11 U10 V10 W10 Schematic Diagram of Star-Delta Starting (Motor Power 15KW) L1 L2 L3 QS FU1 FU2 KH KM SB1 U V W KH SB2 KM KM KM Y Description of Element M 3 ~ KM KT KM Y KH QS FU1-2 Thermal relay Circuit Breaker Fuse KT Delay Contact KM AC Contactor KM Y SB1 SB2 Stop Button Start Button KT KM Y KM KM M1 Fan Motor Function Features: - Fan starting and stopping controlling - Output Power: Direct Starting for KW, star-triangle Starting for 15-55KW - Indication for power, operation, and fault status - Fire alarm interlocking device - Circuit protection for overload, short circuit, anti-phase, loss of phase, overvoltage and undervoltage, voltage imbalance Variable-Frequency Starting/Control A VFD provides adjustable speed control for single fan motor. Normally, an Air T&D AHU which has been installed by VFD can vary the frequency within 30 to 50Hz in order to control motor rotation speed. It also provides protection for the motor operation. VFD 1U X1 COM TA Fire contact K1 FU1 U11 QF11 TC 9 R S T U V W G KM11 N N XT11 Description of Electrical Element XT11 Terminal QF11 Miniature Circuit Breaker U V W M1 Fan Motor M2 3 ~ Heat Elimination Fan M1 3 ~ Fan 1U Transducer K1 Cooling Machine KM11 Auxiliary Contractor with Time L1 L2 L3L N PE FU1 Fuse Notes for Variable-Frequency Starting/Control: Technological Innovation from NTU, Singapore 31

33 - If using variable frequency motor, implement the controlling with the dotted-line part above, and the power is 3/N/PE AC 380/220V 50HZ; - If using the normal motor, no need the controlling of the dotted-line part, and the power is 3/N/PE AC 380/220V 50HZ; - All alarms are inter-locking with Fire control. Electrical Cabinet Installation Position: can be installed on the wall beside the units; Suggesting that the distance between the installation position and fan is less than 3m, height (based on the operation plane) is greater than m. If the wire connecting distance is greater than 3m, the wire connection needs to be done by customers themselves. The routing on site and the materials of duct should be done by customers themselves. 5.2 Automation System All Air T&D handling units come equipped with Air T&D BSTAR software and controller mounted in a control cabinet inside the unit. The controller is accessed by opening the external control cabinet door with an emergency stop button. In order for the unit to run using the BSTAR controller and default controls program, the VFD selector switch must be in remote mode. The unit control program can be accessed using a computer with the Air T&D DAQ tool software and the unit-mounted standalone display. The standalone display is mounted in a sealed cabinet on the front of the unit next to the external disconnect. The operator display touch screen is an intuitive operator interface for monitoring and changing building control functions. With the operator display you can: Choose specific chilled water flow within specified range. Choose specific air flow within specified range. Monitor space temperature, air flow, filter status, etc. Identify and troubleshoot problems. View and reset controller alarms. Field elements Type Elements Function and properties - Two-way: It is used to adjust the flow rate of the water entering the system Actuator Motorized Flow Control Valves Damper Motors proportionally or On/Off controlled. - Three-way: Allows the water coming from the system and the boiler to mix and determines the ratio of mixture. - Normal: Air flow is used to control the control dampers in heating-cooling and ventilation systems. - Spring return: Air flow that has a safety function in heating-cooling and ventilation systems is used to control the control dampers (e.g. freeze protection, smoke control, hygiene). Technological Innovation from NTU, Singapore 32

34 - Duct type: It is used to measure the temperature in ventilation ducts. - Room type: It is used to measure the indoor temperature in Heating-Cooling- Heat Sensors Ventilation systems. - Outdoor type: It is used to measure the outside temperature. - Freeze-free thermostat: It is used to protect the heating coils in the heating-coolingventilation systems against the risk of freezing. Sensor Humidity Sensors Pressure Sensor - Duct type humidity sensor: It is used to measure the indo- or humidity and temperature in Heating-Cooling-Ventilation systems. - Room type humidity sensor: It is used to measure the indoor humidity and temperature in Heating-Cooling Ventilation systems. - Differential pressure switch: It is used to sense the dirtiness of the air filters and determine whether the fans are operating properly or receiving "belt breakage warning. - Differential pressure sensor: It is mainly used to adjust flow rates of the fans and monitor the filter dirtiness in a sensitive way. Controllers Two types of controller were designed by Air T&D to control central air-conditioning and air handling system, i.e., Universal Controller and Terminal Controller. Optoelectronic isolation technology is adapted here to the controller for accurate data acquisition and stable operation. The controllers provided the various data collection ports to satisfy all the central air-conditioning systems. The advantages of the controller are as follow: - Using ARM chips, with more powerful real-time processing capabilities - A more powerful processor, and more analog/digital I/O port - Complex logic arithmetic function - A friendly human-computer interface - Simple, easy networking with RS Low-power design, no heat sink U13 (Universal controller) L13A (Terminal controller) BSTAR Software BSTAR, provided by Air T&D, is a unique project development platform and management system for building automation, which integrates abundant functions such as monitoring, control, optimization, fault detection and diagnosis (FDD), and energy management (EMS) for HVAC systems. Inheriting the following advantages, this platform and its tools bring effective BMS design and facility operation, and will make the buildings Technological Innovation from NTU, Singapore 33

35 more energy-efficient and eco-friendly. Excellent user interface, configurable assembles and competitive integrations. These increase staff productivity, improve plant reliability and life, and save time/money during maintenance. Dedicated and High-valued function modules. Auto-tuning control, FDD, and energy efficiency analysis and optimization fill the gap between industry and academy. Flexible and Extensive. Modular and structured framework facilitates function extensions, and makes it easy to integrate with/into other BMS by the self-defined or third-party plugins. Using this powerful tool software, customers can design basic controls and some advanced functions for Air T&D air handling units: Temperature control Frequency converter operation for constant air flow or duct pressure On-demand control Heating and cooling shunts CO 2-compension of fans Control of different types of heat exchanger Energy measurement Control of extra fans Control of temperature zones Communication via BACnet, or Modbus Monitoring via a C/S or B/S interface The following is a sample HMI drawing for an air handling unit designed with BSTAR. Technological Innovation from NTU, Singapore 34